title: Interresidue distance measurements in proteins. Fluorescent energy transfer between tryptophans and a Ru(III)(NH3)5-histidine complex in alpha-lytic protease and lysozyme.
abstract: The mechanism by which the intrinsic fluorescence of tryptophan residues in alpha-lytic protease and lysozyme are quenched by a complex formed between the single histidine residue in each protein and Ru(III)(NH3)5 was investigated. The R0 values for alpha-lytic protease and lysozyme were 15.5 and 11.8 A, respectively. Good agreement between the efficiency of energy transfer measured experimentally and that calculated from the X-ray data, assuming the Förster dipole-dipole mechanism, demonstrates that this mechanism is appropriate. The ease with which the ruthenium-labeled enzymes can be synthesized and purified suggests that the Ru(III)(NH3)5-His complex may have general utility in structural studies of proteins in solution.
mesh_terms: D000641:Ammonia / Q000494:pharmacology*; D010450:Endopeptidases / Q000378:metabolism*; D004735:Energy Transfer; D006639:Histidine; D007700:Kinetics; D009113:Muramidase / Q000378:metabolism*; D009231:Myxococcales / Q000201:enzymology*; D011485:Protein Binding; D011487:Protein Conformation; D012428:Ruthenium / Q000494:pharmacology*; D012697:Serine Endopeptidases; D013050:Spectrometry, Fluorescence; D014364:Tryptophan; D014961:X-Ray Diffraction
chemical_list: D006639:Histidine; D000641:Ammonia; D012428:Ruthenium; D014364:Tryptophan; D009113:Muramidase; D010450:Endopeptidases; D012697:Serine Endopeptidases; C021826:myxobacter alpha-lytic proteinase